Fan

ABSTRACT

A fan includes a base and an impeller rotatably mounted on the base. The base protrudes a tube outwardly therefrom. The tube defines a receiving hole therein for receiving a bearing. The bearing defines a bearing hole therein. The impeller protrudes a shaft therefrom towards the base. The shaft is rotatably received in the bearing hole. The fan further includes a gasket located at a bottom of the bearing and clipped on a free end of the shaft. The gasket includes a first surface and an opposite second surface. The first surface is a smooth surface and facing directly the bottom surface of the bearing. The second surface is a rough surface relative to the first surface. At least one of the first surface and the second surface is provided with a mark to differentiate the rough second surface from the smooth first surface.

BACKGROUND

1. Technical Field

The disclosure generally relates to fans, and particularly to a fan for dissipating heat of electronic components.

2. Description of Related Art

Generally, a fan includes a housing and an impeller rotatably mounted in the housing. The housing includes a central tube at a central portion thereof. The central tube is cylindrical and defines a receiving hole therein. A bearing is received in the receiving hole of the central tube. The bearing defines a bearing hole therein. A shaft extends downwardly from the impeller towards the housing. The shaft extends into the bearing hole of the bearing with a bottom free end thereof extending out of a bottom surface of the bearing. The fan further includes a gasket. The gasket is clipped on the bottom free end of the shaft to prevent the shaft escaping from the bearing.

The gasket is usually made through punching. In manufacturing the gasket, the punching die becomes blunt gradually due to an abrasion thereof after a long service time. Thus, a rough surface is sometimes formed on a bottom surface of the gasket, and a smooth surface relative to the rough surface is formed on a top surface of the gasket opposite to the rough surface. The gasket is clipped onto the bottom free end of the shaft randomly during assembly of the fan as it is difficult to differentiate the rough surface from the smooth surface of the gasket. When the gasket is clipped on the shaft with the rough surface facing the bottom surface of the bearing, a noise will be caused due to attrition between the rough surface of the gasket and the bottom surface of the bearing.

Therefore, what is needed is a fan which can overcome the above-described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a fan in accordance with an embodiment of the present disclosure.

FIG. 2 is an exploded view of the fan of FIG. 1.

FIG. 3 is an isometric view of a gasket of the fan of FIG. 2.

FIG. 4 is similar to FIG. 3, but showing the gasket in a different view.

FIG. 5 is a cross-section of the fan of FIG. 1, taken along line V-V thereof.

FIG. 6 is an enlarged view of the circled portion VI of FIG. 5.

DETAILED DESCRIPTION

Referring to FIG. 1, a fan according to an embodiment of the present disclosure is shown. The fan includes a housing 10 and an impeller 20 rotatably mounted in the housing 10.

Referring to FIGS. 2 to 5, the housing 10 includes a rectangular sidewall 12 and a base 11 located at a bottom central portion of the sidewall 12. A bearing tube 13 protrudes upwardly from a central portion of the base 11. The bearing tube 13 is cylindrical and defines a receiving hole 14 therein, for receiving a gasket 17 and a bearing 18 therein. The bottom end of the bearing tube 13 is a closed end and defines an oil reservoir 15 therein. The oil reservoir 15 communicates with the receiving hole 14. An inner diameter of the oil reservoir 15 is less than that of the receiving hole 14, and an annular step 16 is formed on an inner wall of the bearing tube 13 between the oil reservoir 15 and the receiving hole 14. A stator 19 is mounted around the bearing tube 13.

The gasket 17 is a circular sheet and made of metal or plastic through punching, and in this embodiment, the gasket 17 is made of polyethylene terephthalate (PET). The gasket 17 includes a first surface 171 and a second surface 172 at two opposite sides thereof. In this embodiment, the first surface 171 is a top surface of the gasket 17, and the second surface 172 is a bottom surface of the gasket 17. The first surface 171 and the second surface 172 are labeled with different color, and in this embodiment, the first surface 171 is yellow and the second surface 172 is red. The gasket 17 defines a through hole 173 therein. An outer diameter of the gasket 17 is no more than the inner diameter of the receiving hole 14 of the bearing tube 13 but larger than the inner diameter of the oil reservoir 15. A slot 174 is defined in the gasket 17 along a radial direction of the gasket 17. The slot 174 runs through the first surface 171 and the second surface 172 of the gasket 17, and communicates with the through hole 173 of the gasket 17, whereby the through hole 173 can resiliently expand properly. In manufacturing of the gasket 17, the first surface 171 of the gasket 17 faces the punching die, the punching die moves from the first surface 171 towards the second surface 172, whereby the yellow first surface 171 of the gasket 17 forms a smooth surface and the red second surface 172 of the gasket 17 forms a rough surface.

The bearing 18 is substantially cylindrical, with a bearing hole 181 defined along an axial direction thereof.

The impeller 20 includes a hub 21 and a plurality of blades 22 extending outwardly and radially from a periphery of the hub 21. A shaft 23 extends downwardly and perpendicularly from the center of the hub 21 towards the housing 10. An annular recess 24 is defined around the shaft 23 in a bottom free end of the shaft 23. An inner diameter of the through hole 173 of the gasket 17 is a little smaller than an outer diameter of the shaft 23 but a little larger than an inner diameter of the annular recess 24 of the shaft 23. The shaft 23 is rotatably received in the bearing hole 181 of the bearing 18 with the bottom free end of the shaft 23 extending out of the bottom surface of the bearing 18. In this embodiment, the bearing 18 is made of porous metal and saturated with lubricant, for lubricating the shaft 23 during rotation of the impeller 20.

Referring to FIG. 6, during assembly of the fan, the gasket 17 is disposed on the step 16 in the receiving hole 14 of the bearing tube 13, with the second surface 172, i.e., the rough surface of the gasket 17 facing the oil reservoir 15 of the bearing tube 13. The bearing 18 is pressed into the receiving hole 14 of the bearing tube 13. The bearing 18 is mounted in the receiving hole 14 through interference fit between the bearing 18 and the inner wall of the bearing tube 13. In this state, the gasket 17 is located between the bottom surface 183 of the bearing 18 and the step 16 of the bearing tube 13 with the first surface 171 i.e. the smooth surface thereof facing the bottom surface 183 of the bearing 18. Then, the shaft 23 of the impeller 20 is inserted into the bearing hole 181 of the bearing 18 until the gasket 17 clips in the annular recess 24 of the shaft 23.

In the present disclosure, the first surface 171 and the second surface 172 of the gasket 17 are marked with different colors, the color of yellow designates the smooth surface, and the color of the red designates the rough surface, whereby the rough surface of the gasket 17 is easily differentiated from the smooth surface of the gasket 17. During assembly of the fan, an operator can properly dispose the gasket 17 in the receiving hole 14 of the bearing tube 13 with the smooth surface facing the bottom surface 183 of the bearing 18 to avoid a noise caused by attrition between the gasket 17 and the bottom surface 183 of the bearing 18 during rotation of the impeller 20.

In the previous embodiment, different colors are used to denote the first surface 171 and the second surface 172 of the gasket 17 to differentiate the rough surface from the smooth surface of the gasket 17. Understandably, a single color can be used to denote which surface of the gasket 17 is or is not the rough surface. For example, the single color can be painted on one surface of the gasket 17 to denote the surface with the single color is a rough surface.

Other marks can also be used to differentiate the rough surface and the smooth surface of the gasket 17. For example, the first surface 171 and the second surface 172 can be provided with different cutting lines, with one type of cutting line denoting the rough surface and the other type of cutting line denoting the smooth surface. Similarly, a single type of cutting lines can be used to denote which surface of the gasket 17 is or is not the rough surface. For example, the single type of cutting lines can be provided on one surface of the gasket 17 to denote the surface with the single type of cutting lines is a rough surface.

It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A fan comprising: a base with a bearing tube protruding outwardly from the base, the bearing tube defining a receiving hole therein, a bearing received in the receiving hole, the bearing defining a bearing hole therein; an impeller rotatably mounted on the base, a shaft protruding from the impeller towards the base, the shaft being rotatably received in the bearing hole; and a gasket received in the receiving hole and located at a bottom surface of the bearing, and the gasket being clipped on a free end of the shaft, the gasket comprising a first surface and an opposite second surface, the first surface being a smooth surface and facing the bottom surface of the bearing, the second surface being a rough surface relative to the first surface, at least one of the first surface and the second surface being provided with a mark to differentiate the rough second surface from the smooth first surface.
 2. The fan of claim 1, wherein the mark is a color mark.
 3. The fan of claim 2, wherein only one of the first surface and the second surface is marked with a color mark.
 4. The fan of claim 1, wherein the first surface and the second surface are marked with different cutting lines as the differentiating marks.
 5. The fan of claim 1, wherein only one of the first surface and the second surface is marked with a type of cutting lines as the mark.
 6. The fan of claim 1, wherein the gasket defines a through hole and a slot therein, the slot runs through the first surface and the second surface of the gasket and communicates with the through hole, the shaft of the impeller defines an annular recess at the free end thereof, the shaft extends through the through hole of the gasket, and the gasket clips in the recess of the shaft.
 7. The fan of claim 1, wherein the bearing tube comprises a closed end, an oil reservoir is formed in the receiving hole near the closed end, the oil reservoir communicates with the receiving hole, an inner diameter of the oil reservoir is smaller than that of the receiving hole, and an annular step is formed on an inner wall of the bearing tube between the oil reservoir and the receiving hole, the gasket is located between the bottom surface of the bearing and the step of the bearing tube.
 8. The fan of claim 1, wherein the gasket is made of metal or plastic.
 9. The fan of claim 8, wherein the gasket is made of polyethylene terephthalate.
 10. The fan of claim 1, wherein the gasket is made through punching. 